| A finite element code based on interlaminar shear stress continuity and interlaminar displacement discontinuity conditions and presented by Lee was utilized in the thesis research to analyze the in-plane damage and interfacial condition of a composite laminate subjected to blast loading. The displacement discontinuity conditions between different composite plies were enforced by using both shear slip approach and embedded layer approach. The delamination scheme was validated for a composite plate subjected to sinusoidal loading by an elasticity solution extended from the Pagano's problem. For perfectly bonded composites, the finite element solutions matched well with the elasticity solutions given by Pagano. However, for imperfect bonding conditions, the finite element model could only account for the shear slip across the interfaces, but not the normal separation. To understand the nature of blast loading, a brief explanation about the pressure profile and other parameters involved in blast waves was elaborated. Numerical results obtained by simulating the blast loading on composite laminate were presented. Various in-plane and delamination failure criteria were applied using these results. Although the numerical results for interlaminar analysis agreed with that of experiment, the numerical results for in-plane analysis did not match with that of experiment. Absence of geometric non-linearity in the laminate theory and coupling between in-plane stretching and out-of-plane deflection were considered to be the sources of discrepancy. |
